#VU103047 Buffer overflow in Linux kernel - CVE-2025-21648

Vulnerability identifier: #VU103047

Vulnerability risk: Low

CVSSv4.0: 4.3 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2025-21648

CWE-ID: CWE-119

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Linux kernel
Operating systems & Components / Operating system

Vendor: Linux Foundation

Description

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to memory corruption within the nf_ct_alloc_hashtable() function in net/netfilter/nf_conntrack_core.c. A local user can perform a denial of service (DoS) attack.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: All versions

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External links
https://git.kernel.org/stable/c/5552b4fd44be3393b930434a7845d8d95a2a3c33
https://git.kernel.org/stable/c/b541ba7d1f5a5b7b3e2e22dc9e40e18a7d6dbc13
https://git.kernel.org/stable/c/d5807dd1328bbc86e059c5de80d1bbee9d58ca3d
https://git.kernel.org/stable/c/f559357d035877b9d0dcd273e0ff83e18e1d46aa

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.